The social defence institution of Paifve is the only SDI dependent on the FPS Justice. It was conceived in the late fifties and its ground was bought in the early sixties, before the law of 1966 on the use of languages in administrative matters was published.In the beginning, it was designed to gather all French-speaking and Dutch-speaking confined men. This purpose explains why the institution is located away from the centre of the country, but at a few hundreds of meters of the linguistic boundary.Built in the early seventies by the Buildings Agency, it was opened in 1972. The SDI is thus devoted to French-speaking confined men only. From 1972 to 1975, the institution accommodated some correctional offenders sentenced to light sentences and Jehovah’s Witnesses who were employed for the inner and outer fit-up of the estate and the wards. The institution has been exercising its specific function of SDI since 1976 only, when the first confined persons arrived from Tournai and Merksplas. From 1979 to 1983, the SDI also had to take in the psychiatric ward of the prison of Lantin, which was new, but not entirely functional yet. The SDI has been exclusively taking in confined persons since 1983 only.